A conventional turbine engine has a compressor section, a combustor section and a turbine section. In operation, the compressor section can induct ambient air and compress it. The compressed air can enter the combustor section and can be distributed to each of the combustors therein. When the compressor discharge air enters the combustor, it is mixed with fuel supplied by a pilot nozzle and a plurality of main nozzles surrounding the pilot nozzle. Combustion of the air-fuel mixture occurs downstream of the nozzles in a combustion zone, which is largely enclosed within a combustor liner assembly. As a result, a hot working gas is formed. The hot working gas can be routed to the turbine section, where the gas can expand and generate power that can drive a rotor.
During engine operation, cylindrical components and rotatory components are rotated to move air and fuel through the engine. Such rotation causes vibrations inside the turbine engine. The vibrations can cause components of the engine to vibrate out of place or out of alignment. Additionally, the fluid movement within the engine also causes temperature changes within the engine. Such temperature changes can change the material properties of the engine components, thereby increasing the likelihood that those components can become misaligned or disengaged from their couplings or attachment points.
Conventional turbine engines can include rotary vanes and stationary vanes. Typically, a stationary vane assembly includes individual vanes assembled between an inner shroud ring and an outer shroud ring. Combustion gas passes through the annular path between the shroud rings and over the vanes. The vane assembly can include coolant outlets to allow coolant to flow radially inward through the vanes to coolant outlets. The coolant outlets can be open to a cavity formed between a rim-cavity seal and the outer shroud ring of the vane assembly. For example, in one implementation, the rim-cavity seal can be a U-ring, and a plenum can be formed between the U-ring and the outer shroud ring. The plenum can provide a cavity for return or exhaust of the coolant.
The rim-cavity seal and the stationary vane assembly are typically secured together by two pins. One pin is inserted between the outer shroud ring and the rim-cavity seal to prevent rotation of the vane assembly, and a second pin is inserted to maintain the first pin in place and to prevent the first pin from being extracted during engine operation. While the two-pin assembly restrains the motion of the vane assembly and prevents the extraction of the pin during engine operation, the two-pin assembly requires an extra component, thereby resulting in a cumbersome, expensive, and time-intensive assembly and disassembly process when the stationary vane assembly needs to be serviced.
In another conventional assembly, an anti-rotation pin is inserted between the outer shroud and the rim-cavity seal, and the head of the anti-rotation pin is deformed. In such an assembly, metal is staked around the pin. However, while the deformed anti-rotation pin prevents rotation of the vane assembly, the vibration and thermal environment of the engine during operation causes the anti-rotation pin to become disengaged.
Accordingly, there is a need for a vane assembly that can minimize the above-described concerns. To address the above described shortcomings, the present disclosure provides an enhanced self-locking anti-rotation pin for a turbine engine vane assembly that is cost-effective and less cumbersome to assemble and disassemble as compared to conventional vane assemblies.